2,313 research outputs found

    Optimization of glucose oxidase production by Aspergillus niger

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    The glucose oxidase was produced by fermentation using Aspergillus niger isolated from potato as producer organism and glucose as the carbon source (substrate). Maximum production of the enzyme (1.59 ìmoleHQMin-1ml-1) was achieved at 10% glucose concentration after 48 h of submerged fermentation. The pH for the optimal production of enzyme was found to be 5.5 (enzyme activity 1.56 ìmoleHQMin-1ml-1). Addition of urea (0.2%) and KH2PO4 (0.4%) into the fermentation medium increases enzyme activity (2.01 and 2.96 ìmoleHQMin-1ml-1, respectively) while MgSO4·7H2O was found to inhibit GOX production by A. niger.Key words: Glucose oxidase, Aspergillus niger, glucose oxidase

    Molecular basis of arsenite (As+3)-induced acute cytotoxicity in human cervical epithelial carcinoma cells

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    Background: Rapid industrialization is discharging toxic heavy metals into the environment, disturbing human health in many ways and causing various neurologic, cardiovascular, and dermatologic abnormalities and certain types of cancer. The presence of arsenic in drinking water from different urban and rural areas of the major cities of Pakistan, for example, Lahore, Faisalabad, and Kasur, was found to be beyond the permissible limit of 10 parts per billion set by the World Health Organization. Therefore the present study was initiated to examine the effects of arsenite (As+3) on DNA biosynthesis and cell death.Methods: After performing cytotoxic assays on a human epithelial carcinoma cell line, expression analysis was done by quantitative polymerase chain reaction, western blotting, and flow cytometry.Results: We show that As+3 ions have a dose- and time-dependent cytotoxic effect through the activation of the caspase-dependent apoptotic pathway. In contrast to previous research, the present study was designed to explore the early cytotoxic effects produced in human cells during exposure to heavy dosage of As+3 (7.5 μg/ml). Even treatment for 1 h significantly increased the mRNA levels of p21 and p27 and caspases 3, 7, and 9. It was interesting that there was no change in the expression levels of p53, which plays an important role in G2/M phase cell cycle arrest.Conclusion: Our results indicate that sudden exposure of cells to arsenite (As+3) resulted in cytotoxicity and mitochondrial-mediated apoptosis resulting from up-regulation of caspases.Keywords: apoptosis; epithelial carcinoma; cytotoxicity; arsenite; caspases; Pakistan Responsible Editor: Amin Bredan, VIB Inflammation Research Center & Ghent University, Belgium

    Dose Determination of Activated Charcoal in Management of Amitriptyline-Induced Poisoning by Reversed-Phase High-Performance Liquid Chromatography

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    Purpose: To assess the doses of activated charcoal currently used in the management of acute amitriptyline-induced drug poisoning and explore the possibility of using lower doses.Methods: Albino male Wistar rats, weighing 200 ± 20 g, were used for the study. The animals were divided into four groups of eight animals each. The concentration of amitriptyline in rat plasma was measured by high performance liquid chromatography (HPLC) for dose determination of activated charcoal. Chromatograms were established with acetonitrile: 70 mM KH2PO4 buffer (60: 40, v/v) solvent system on an Xterna® ms C18 SUM column (5 μm, 3.9 × 150 mm) and pH was adjusted to 4.5 with ortho-phosphoric acid. Mobile phase flow rate was 1 ml/min and ultraviolet (UV) detection was at 293 nm. Validation of the method was performed to determine its selectivity, linearity, precision, as well as limits of detection (LOD) and of quantification (LOQ).Results: Standard curves were linear, r2 = 0.996, for amitriptyline over the concentration range 10 - 60 ng/ml. Recovery (98.3 to 100.85 %) was in the selected concentration range of 10 - 60 ng/ml. The LOD and LOQ of the method for amitriptyline were 0.109 and 0.332 μg/ml, respectively. The validated method was successfully applied to measure plasma concentrations of amitriptyline and to measure the doses of activated charcoal currently used in the management of acute amitriptyline drug poisoning.Conclusion: The proposed RP-HPLC method enables determination of amitriptyline with good separation and resolution of the chromatographic peaks. Validation revealed that the method is sensitive, accurate and selective. Using half of the standard dose of the activated charcoal gave a comparable effect to the standard dose in reducing drug concentration in the blood. While, using quarter of the standard dose of activated charcoal does not have a cleared effect.Keywords: Amitriptyline, Activated charcoal, Drug poisoning, Reversed-phase high-performance liquid chromatograph

    Living with Coronavirus (COVID-19) : a brief report

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    The world will never be same after the current COVID-19 pandemic. We may have to live with the coronavirus for a long time. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has resulted in a major burden on the global health system and economy. This report describes the current COVID-19 landscape and its socioeconomic implications. Despite the concerns for second waves of infection, gradual lifting of lockdown restrictions has occurred worldwide to relieve economic pressures and likely contributes towards possibly seen the sudden up surging of outbreak although region wise variation exists due to several other biological factors such as testing capacity and basic healthcare facilities among susceptible population within that region. Different prediction models have been put forth to forecast the spread of the current outbreak. However, it is challenging to perceive the precise changes happening in the real world as every time dynamics differ same as other epidemics cannot possibly be exactly superimposed to COVID-19. Currently, to decrypt the conundrum for effective antiviral drug against SARS-CoV-2 is in full swing. Due to high rate of mortality and it expeditiously spread is it decisive to understand the biological properties, clinical characteristics, epidemiology, evolution, pathogenesis for vaccine development and pathogenicity studies against the viral curb. Instant diagnostic and adequate therapeutics serve as a major intervention for the management of pandemic containment. Our study aims to analyze the impact of current measures and to suggest appropriate administrative strategic planning rather than to make somewhat authentic prediction in relation to the current scenario. We hope that our predictive analysis study will be helpful against prevention, cure and control of current outbreak of COVID-19 till the availability of cure or vaccine

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

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    The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO

    Compressed representation of a partially defined integer function over multiple arguments

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    In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one

    Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

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    A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter
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